Furnace door



July 19, 1-938II l.. R. McAFoos FURNAGE DOOR Filed may -11, 19:57

IINN lNvr-:N'ro'R Lan/fen caRMQAfoos YMIMTFM Patented July 19,1938 I l UNITED vSTATES PATENT-voFFlfcI-l -FURNAGE Doon Lawrence R. McAfoos, Pittsburgh, Pa., assgnortc Reliance Steel Products Company, Rankin, Pa., a corporation of Pennsylvania Application May 11, 1937, Serial No. 141,907

` 2 claims. (01.122-498) This invention relates to furnace doors of the In the accompanying drawing illustrating a type used in furnaces in which comparatively present preferred embodiment of my invention: high temperatures are encountered, and particu- Figure 1 is an elevation of a water-cooled larly to those furnaces which are employed in furnace door; and 5 heating and melting metals. In furnaces used for Figure 2 is a sectional view along the line II--II 5 l heating or melting metals, it isdesirable to conof Figure 1. trol the inflow of atmospheric air both as to place In the drawing, there is shown a water-cooled of ingress and as to quantity. Thus, it has been furnace door formed of rolled steel welded to- 1 found that it is very undesirable, in general, to gether at appropriate places and indicated genallow air to leak into the furnace around the erally by the reference character 3. The door 10 Ifurnace doors, as the effect on the heated metals consists of an outer plate 4 and an inner plate 5, of unknown quantities of air cannot be foreseen secured at its edges to the plate 4 by a weld 6. and this leads to metallurgical difficulties and The main portions y,of the plates are separated loss of efficiency in the operation of the furnace. from one another and secured at intermediate By preventing infiltration of air, it is possible to points by appropriate stay bolts l. The plates 'l5 better regulate combustion with a consequent fuel 4 and 5 are shaped so as to provide between the saving and to better control the furnace operation main panel portions a. main water space 8 and bewhich gives a superior product. It is also of tween the edge portions a peripheral water space importance that the heat of the furnace be con- 9, which extends'around the periphery of the door u served and leakage of heated gases around the and projects beyond the main water space 8. The 20 edges of the furnace door prevented, as such leakplate 5 is shaped so as to provide a reentrant age represents a direct heat loss, is injurious to space Ill, in which a refractory such as rebrick the furnace structure, and increases rthe diflimay be placed, if desired.

culties underwhich the workmen must labor. It The outer plate 4 projects beyond the inner is thus apparent that it is of advantage that the plate 5 and has a lip or sealing edge Il, which is 25 doors used in such furnaces be so designed and comparatively narrow and which projects in a constructed as to prevent gas leakage into and direction normal to the plane of the face of the out of the furnace. door. The sealing or wearing edge Il contacts In the commercial operation of furnaces, it has theface of the furnace door frame' (not shown) been found difficult to keep a reasonably tight in which it` may be mounted when the door is in 30 seal between the furnace door and the furnace position in the furnace. On account of the comdoor frame, and especially is this true after the parative thinness of the wearing edge, it is a door or door frame has been in use for a short simple matter to form a leak-proofl seal with the period of time. door frame and should warpage occur, the sealing I provide a door which has a thin projecting edge will readily adapt itself to the contour of the 35 I portion around the edges thereof, which projectdoor frame. If unusual warpage occurs, the edges lng portion contacts the furnace door frame. The may be readily shaped as required by grinding or narrow edge will readily adjust itself tothe conmachining, to insure a tight contactwith the flat tour of the door frame and provide a comparadoor face of the door frame. In the event that li0 tively tight seal. If undue warping takes place the edge ll wears to a point where it is substan- 40 either in the door or frame, or in both, the door tially flush with the portion of the inner plate 5 can be removed and the projecting edges shaped nearest the furnace door frame, it is a very easy to provide a satisfactory seal between the door matter to replace or restore the projecting edge by edge and the frame. The edge can be readily rewelding an appropriate thin strip to the furnace newed should the occasion arise by welding an door. Indeed, the projecting lip or wearing edge 45 appropriate strip around the edges of the door. Il may, in the rst place, be formed by welding By this construction, the furnace door can be an appropriate strip to the furnace door instead made substantially gas-leak-proof, since it is of allowing the outer plate 4 to project, as shown'. much easier to form and maintain a seal between A water inlet pipe. l2 extends into one leg of the a narrow edge and a flat surface than between peripheral water space 9 to a point adjacent the 50 two flat surfaces. The disadvantages due to lower side of the door. A discharge pipe I3 is.

furnace door leakage can thus be avoided and` also provided at the upper side of the door. The

the working conditions of the Workmen and the use of such circulation pipes is familiar and any operation of the furnace, and consequently, the desired arrangement of them may be adopted.

product, will be improved. Y An opening I4 is provided through the door 2, 55

which opening is closed by means of a swinging cover I5, in which the usual peep holes I6 are formed. Lifting lugs I1 are secured to the upper side of the door.

While I have illustrated and described a preferred embodiment of my invention, it Will be understood that it is not limited thereto, but may be otherwise embodied and practiced Within the scope of the following claims. Y

I claim:Y

1. A furnace door comprising a main panel portion and a peripheral edge portion, said edge portion terminating inwardly in a comparatively.

thin wearing edge which projects in a direction l5 normal to the plane of the face fof the door so that the edge is in position to slidably move along and to bear against a furnace door frame in which the door may be mounted.

2. In a Water-cooled furnace door, an outer plate and an inner plate, said plates enclosing a main water `space and a peripheral Water space, and a thin Wearing edge around the Whole periphery of the door projecting inwardly in a, direction normal to the plane of the `face of the door from a point on the door adjacent the peripheral water. space, so that the edge is in position to slidably move along and to bear against a frame in which the door may be mounted.

LAWRENCE R. McAFoos. 

